Polar Biology (1997) 17:296-304
Diving and foraging behavior of Adelie penguins an areas with and without fast sea-ice
Yutaka Watanuki, Akiko Kato, Yasuhiko Naito, Graham Roberston, Sue Robinson
The diving and foraging behavior of Adelie penguins, Pygoscelis adeliae, rearing chicks at Hukuro Cove, Lutzow-Holm Bay, where the fast sea-ice remaind throughout summer, were compared to those of penguins at Magnetic Island, Prydz Bay, where the fast sea-ice disappeared in early January. Parent penguins at Hukuro Cove made shallower (7.1-11.3m) but longer (90-111 s) dives than those at Magnetic Island (22.9m and 62 s). Dive duration correlated with dive depth at both colonies (r2=0.01-0.90), but the penguins at Hukuro Cove made longer dives for a given depth. Parents at Hukuro Cove made shorter foraging trips (8.1-14.4 h) with proportionally longer walking/swimming (diving <1m) travel time (27-40% of trip duration) and returned with smaller meals (253-293g) than those at Magnetic Island, which foraged on average for 57.2 h , spent 2% of time walking/swimming (<1m) travel, and with meals averaging 525g. Trip diration at both colonies correlated to the total time spent diving. Trip duration at Hukuro Cove, but not at Magnetic Island, increased as walking/swimming (<1m) travel time increased. These differences in foraging behavior between colonies probably reflected differences in sea-ice cover and the availability of foraging sites.
PG97-1
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